The new 8.6 code and above offers support for a GYRO.  The GYRO is intended to keep the mower in straight line on sloping terrain (SWOBY build).  Here is the connection diagram for the GYRO.  

The GYRO needs to be bridged between AD0 and VCC to give it another i2C address, otherwise this will conflict with other components in the mower.  There is also an optional 10K pull up resistor set which can be installed.  Reason is explained here.  Im not sure if the 10K pull up does anything or is even necessary hence the "optional".


To create the 10K pull up resistor solder the resistors as shown below and cover with heat shrink tube.